JPS6092024A - Blanking device - Google Patents

Abstract

PURPOSE:To prevent scum riser of slug and stabilize blanking work by providing a sectional die provided with a blanking hole having specified clearance on outer periphery of a punch in a deviated form and making a stepped part in the blanking hole. CONSTITUTION:The die 12 has a blanking hole 14 that can be fitted to the outer periphery of the punch 11 keeping specified clearance alpha. Angle of relief beta is set to the blanking hole 14, and a stripper 16 presses and fixes a material 13 by a spring 17 prior to blanking. The die 12 is a sectional die that divides inner periphery of the blanking hole 14 by a dividing line 19. When the punch 11 descends for blanking, the B part descends with the punch 11 in the blanking hole 14 and bites the stepped part 20. Even if the punch 11 is raised, the slug is not pressed out on the die 12 and scum riser is prevented. Thus, stable blanking work can be performed without generating inferior products and breakage of die etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a punching device which improves the ability of a split die formed in a punched shape to absorb punched scraps and prevents scraps from rising from the die. .

[Technical background of the invention and its problems]

When punching is performed using a press machine, a plate-shaped material is set on a die, and after being pressed and fixed with a stripper, the material is punched out with a punch. In this case, the punched scraps fall together with the punch into a large punched circle formed in one die and are removed.

During the above-mentioned punching operation, punching debris sometimes gets caught in the punch, and once it descends into a large punching circle with the punch, it protrudes from the die as the punch returns and rises. So-called scrap build-up may occur.

When this residue builds up, the product may be defective and the mold may be damaged.

Various methods have been devised to prevent such build-up of waste. for example,? Figure 1 (αHJ (as shown by C1, the punching hole α of the die (121) for the punch (11)
Some types have a convex part (14 cL) or a concave part (14 cL) on the inside of the hole to increase the area for biting into the scraps. Although both of these configurations are effective in preventing scraps from rising,
A convex part (14α) or a concave part (14
4) It requires a lot of man-hours to form.

In addition, as shown in Figure 2, the punch hole 0 (a) of the die az
Some have the same inner diameter from the inlet to the outlet.

In this case, machining of the punch hole α4 is easier than any of the others. Further, the punched waste has almost the same shape and dimensions as the punched hole α4, so after punching, it stops in the punched hole α(a), is pushed by the thickness of the material in the next punching, and then descends. For this reason, scraps are unlikely to rise, but the punched scraps may become stuck in the hole of the punched hole, and if you force the scraps down, the die will wear out very quickly, and the punch will The required pressure gradually increases and may eventually lead to breakage of the punch or die f121. This is a phenomenon called scum clogging. To prevent this, the cutting edge cannot be made long from the inlet to the outlet, making it unsuitable for mass production.

Furthermore, as shown in Figure 16, the die (1z punch hole (14)
1 is a parallel part having a certain length from the entrance, and the part downward therefrom is formed into a tapered shape with an angle β). In this case, the punched scraps are held in the upper parallel part, and are allowed to fall from the lower corner corner V91 each time the punch is punched. However, in order to form the die cut hole I as described above, the parallel part must be machined after machining the cut angle (B), which increases the number of man-hours considerably. .

[Purpose of the invention]

The purpose of the present invention is to improve the ability to stick to the punched scraps in the punched hole, thereby preventing scraps from rising, thereby preventing the occurrence of defective products and mold damage, and enabling stable and smooth processing. An object of the present invention is to provide a punching device.

[Summary of the invention]

A punching device according to the present invention includes a punch and a split die having a punching hole that can be fitted with a predetermined clearance on the outer periphery of the punch, and the inner periphery of the punching hole is divided into a plurality of parts. The split dies are assembled so as to be shifted in the direction of the split line, and a stepped portion is formed on the inner peripheral surface of the punched hole, and the punched waste bites into this stepped portion and protrudes from the die. This prevents debris from rising.

[Embodiments of the invention]

Hereinafter, the present invention will be described in detail with reference to an embodiment shown in the drawings.

In Figure 4, the punching device according to the present invention also has a punch (II
) and die 02, and this die a2 has a needle extraction hole (1 (a)) that can be fitted with a predetermined clearance (α) on the outer periphery of the punch OB.The above-mentioned clearance μ
) varies depending on the type, hardness, thickness, use, etc. of the material 031, but is set in the range of about 2 to 18% in normal punching. Also, the clearance (α) increases due to magical wear during use, so when mass producing it, it is initially set to a small value.

Then, when it is desired to determine the external dimensions of the product, the die I'lJ is made to a predetermined size, and when it is a hole shape, the punch αB is made to a predetermined size, and the punch αυ or die σ2 is made smaller or larger by the amount of clearance.

In addition, the punching hole α4 is set with a punching angle (A) that expands in a tapered shape toward the punching direction (downward in the figure) by the punch αD. Prior to this, the material t13 is pressed and fixed by the spring η.

Here, as the die-cutting, as shown in Fig. 5,
A so-called split die is used in which the inner periphery of the punch hole α is divided into two parts as shown by dividing lines σ■. The reason for using this split die is as follows. In other words, since the punch 01) is generally processed to form the outside, it is easy to perform processing such as grinding even if the shape is very complex, but the die Q2 is processed internally to create a round hole, so it is difficult to process it as a single piece. However, the shapes and processing methods are limited. However, if the shape is split, processing such as grinding becomes easier even if the shape is complex, and it can be made accurately and quickly. It is also easy to adjust for minute eye differences,
Furthermore, there is less damage caused by breakage.

In addition, in the present invention, when assembling such split dies (I-shaped), they are assembled while being shifted along the direction of the dividing line α9, and a stepped portion is formed inside the punch hole αa. The part ('4) is for eating up the punching dregs that have entered the punch hole α4 from the punch K.

That is, when punching is performed, the punch I is lowered in the direction of arrow [F] as shown in Fig. 4. At this time, part A of the material α is held down by the stripper (IQ) and received from below by die α2, so it does not move even when the punch t1υ descends.Therefore, only part B, which becomes the scrap, is removed by the punch αD. , and descends into the punch hole a together with the punch αB.

Here, the inner surface of the punch hole (141) has a stepped portion (
A) is formed along the punching direction, so the punching debris that has fallen into the punching hole I will bite into this step (20). Therefore, even if the punch 01 is raised and returned, No debris will protrude onto the die 112.

In this case, the amount of shift of the punch [center (I) of the punch hole α (A) of the split die 03 with respect to the center (0) of the punch [0]
The clearance is limited to 60-50% of the river. Therefore, the height (■) of the step (2) is determined by the clearance (60 mm
~100%. If the above-mentioned smoothing amount (■) is too small, the scraps will not be picked up, and if it is too large, the clearance (light) will disappear on one side, and the clearance (μ) on the other side will become too large, causing the difference between the punch Qll and the die uz. Galling occurs between the parts, the number of fractured surfaces increases, and the number of burrs increases. Therefore, when setting the amount of shift, it is necessary to take these into consideration and carefully set it within the above range.

Regarding the above relationship, an example will be explained in which the applicant actually tried it and obtained good results. In other words, one is an example of cutting out a semiconductor lead frame, and one has a clearance (C4 is 0.015i
For xIC, the stepped portion (height 2 of 2G) was set to 0.01 crane. Another example is that the height of the stepped section (201) is 0.015 m while the clearance section is 0.02 mm.

As a result, the punched scraps could be reliably stuck to the stepped portion (a) without any problems such as galling between the punch (11) and the die [121], and scraps could be prevented from collapsing.

Note that when punching is performed as described above, the product has a shape approximately equal to that of the punch 0, and the punched waste has approximately the same shape as the die σ2. Therefore, even if a stepped portion is provided, the shape of the product is not affected.

〔Effect of the invention〕

As described above, according to the present invention, the split die is shifted in the direction of the split line to provide a step inside the normally flat punched hole, so when punching with a punch, the punched dregs are removed from the corners of the step. It does not protrude from the die even when the punch is blown and the punch is raised backwards, which effectively prevents the production of defective products and damage to the mold, and enables stable and smooth machining.

[Brief explanation of drawings]

Figure 1 (α) (J) (C), Figures 2 and 3 are plan views showing the conventional structure for preventing scrap build-up, and cross-sectional views, Figure 4 is a punching according to the present invention. 5 is a side sectional view showing one embodiment of the apparatus, and FIG. 5 is a plan view showing the main part of FIG. 4. I...Punch, (13-・split die, I・1 punch hole,
Sumi 1...Dividing line, (to)...Danbe. October 24, 1980 Inventor: Doi Hatsu Male Patent applicant: Tokyo Shibaura Electric Co., Ltd.

Claims (1)

[Claims] +11 A punch, and a split die having a punch hole on the outer periphery of the punch that can be fitted while maintaining a predetermined clearance, and the inner periphery of the punch hole is divided into a plurality of parts, the split die being , are combined and shifted in the direction of the dividing line,
A punching device that has a step formed on the inner peripheral surface of the punched hole.